Piaggio P.X

{{Short description|1930s Italian aircraft piston engine}} {{Distinguish|text = Piaggio Vespa PX Stella or Stella PX}} {{infobox aero engine | name = Stella P.X | image = File:Phyrexian - Marina militare 000.jpg | caption = A close-cowled P.X fitted to an IMAM Ro.43 in 1940 |engine_type = Air cooled radial |national_origin = Italy |manufacturer = Piaggio |designer = Renzo Spolti |first_run = |major_applications = IMAM Ro.43 |status = |produced = |number_built = |developed_from = Piaggio Stella P.IX |variants_with_their_own_articles = |developed_into = }}

The '''Piaggio P.X''', or '''Piaggio Stella P.X''', was an Italian nine-cylinder radial aircraft engine produced by Rinaldo Piaggio S.p.A. Based on experience license-producing Gnome et Rhône designs, the engine was used to power a number of aircraft during World War II, including the IMAM Ro.37bis and IMAM Ro.43, used extensively by the Regia Aeronautica and Regia Marina respectively.

==Design and development== Piaggio acquired a license from Gnome et Rhône in 1925 for their engines derived from the Bristol Jupiter.{{sfn|Gunston|1986|page=125}} The designs proved successful and, using this experience, the company designed a range of related radial engines named "Stella", meaning star.<ref name=museo>{{cite web|title=PXI RC40 engine|website=Museo Piaggio|url=https://www.museopiaggio.it/en/modelli/piaggio-en|archive-url=https://web.archive.org/web/20170826223515/http://www.museopiaggio.it/en/modelli/piaggio-en|archive-date=26 August 2017|access-date=27 March 2020|url-status=live}}</ref> The design was led by the engineer Renzo Spolti.{{sfn|Angle|1939|page=584}} The engines were initially known by their number of cylinders, so the first nine-cylinder model in the range was the P.IX of 1933. However, a progressive number in Roman numerals was used as the design progressed, so the P.IX was followed by the P.X.<ref name=museo />

The Stella P.X was a nine-cylinder version of the P.VII.{{sfn|Wilkinson|1945|page=60}} It retained the same bore and stroke as the original Gnome-Rhône designs, {{convert|146|mm|in|abbr=on}} and {{convert|165|mm|in|abbr=on}} respectively, but was substantially more powerful than the comparable 9K.{{sfn|Angle|1939|page=584}} The engine had a two-piece aluminium-alloy crankcase, steel barrels for the cylinders, and aluminium-alloy heads. A Piaggio T2-80 updraught carburettor was fitted.{{sfn|Wilkinson|1945|page=302}} The basic version, the R., had reduction gear, while the R.C. was also equipped with a compressor.<ref name=museo />

The engine powered the Italian aircraft that served during World War II.{{sfn|Green|1967|page=111}} The IMAM Ro.43 was particularly noteworthy for its performance in the Battles of Cape Spartivento and Cape Matapan.{{sfn|Sadkovich|1994|page=98}}

==Variants== ;P.X R.: Normally aspirated and geared. ;P.X R.C.15: Supercharged and geared, rated at {{convert|1500|m|ft|abbr=on}}. ;P.X R.C.35: Supercharged and geared, rated at {{convert|3500|m|ft|abbr=on}}.

==Applications== * IMAM Ro.37bis * IMAM Ro.43 * IMAM Ro.44 * Savoia-Marchetti S.73 * Savoia-Marchetti S.74 * Savoia-Marchetti SM.81

==Specifications (R.C.35)== {{pistonspecs|  |ref=''Wilkinson, 1945'' {{sfn|Wilkinson|1945|page=302}} |type= 9-cylinder, single row, air cooled radial engine |bore= {{convert|146|mm|in|abbr=on}} |stroke= {{convert|165|mm|in|abbr=on}} |displacement= {{convert|24.9|L|in3|0|abbr=on}} |length= {{convert|1408|mm|in|abbr=on}} |diameter= {{convert|1280|mm|in|abbr=on}} |width= |height= |weight= {{convert|430|kg|lb|abbr=on}} |valvetrain= 2 x overhead valves per cylinder operated by rockers and pushrods |supercharger= Centrifugal compressor |turbocharger= |fuelsystem= |fueltype= 87 Octane petrol |oilsystem= |coolingsystem= Air-cooled |power= <br> ** '''Take-off: ''' {{convert|640|hp|kW|0|abbr=on}} at 2,250 rpm ** '''Cruise: ''' {{convert|450|hp|kW|0|abbr=on}} at 1,800 rpm at {{convert|3500|m|ft|abbr=on}} |specpower= |compression= 6.0:1 |fuelcon= |specfuelcon= 300 g/kWh (0.48 lb/(hp·h)) |oilcon= 8 g/kWh (0.018 lb/(hp·h)) |power/weight=

|designer= |reduction_gear=

|general_other= |components_other= |performance_other= }}

==See also== {{aircontent  |see also=

|related= *Piaggio Stella P.IX

|similar aircraft=

|lists= *List of aircraft engines

|similar engines= *Gnome-Rhône 9K *Nakajima Kotobuki *Pratt & Whitney R-1340 Wasp

}}

==References== ===Citations=== {{reflist}}

===Bibliography=== *{{cite book |first= Glenn Dale |last=Angle |title=Aerosphere |year=1939 |place=New York }} * {{cite book |last=Green |first=William |title=War Planes of the Second World War: Volume Six – Floatplanes |publisher=Macdonald |place=London |date=1967 |isbn=978-3-56014-509-1 }} * {{cite book |last=Gunston |first=Bill |author-link=Bill Gunston |title=The Illustrated Encyclopedia of Combat Aircraft of World War II |place=London |publisher=Salamander Books |year=1978 |isbn=978-0-86101-017-2 }} *{{cite book |first=Bill |last=Gunston|title=World Encyclopedia of Aero Engines |place=London |publisher=Guild Publishing |year=1986 |isbn=978-0-85059-717-2 }} * {{cite book | last=Sadkovich |first=James |title=The Italian Navy in World War II |place=Westport |publisher=Greenwood Press |year=1994 |isbn=978-0-31328-797-8 }} * {{cite book |last=Thompson |first=Jonathon W. |title=Italian Civil and Military Aircraft 1930–1945 |year=1963 |publisher=Aero Publishers Inc. |location=USA |isbn=978-0-81686-500-0 }} * {{cite book |last=Wilkinson |first=Paul Howard |title=Aircraft Engines of the World |publisher=Paul H. Wilkinson |place=New York|year=1945 |url=https://archive.org/details/in.ernet.dli.2015.205335 |access-date=27 March 2020 }}

P.X Category:Aircraft air-cooled radial piston engines Category:1930s aircraft piston engines Category:Nine-cylinder engines

Piaggio P.X

Connections

Linked from

Links to (27 total)